Workpiece treatment machine with discharge means

ABSTRACT

A workpiece treatment machine wherein a workpiece holding basket is retained between a pair of rotatable support elements and wherein said basket is pivotally connected to the elements near its periphery and otherwise releasably connected to the support elements so that as they are rotated in a particular direction the basket will roll out from the machine for treatment.

United'States Patent 1191 Walker 1 June 11, 1974 WORKPIECE TREATMENT MACHINE WITH DISCHARGE MEANS [76] Inventor: Helen H. Walker, 607 Charlton St.,

Valdosta, Ga. 31601 I [22] Filed: Sept. 19, 1972 [21] Appl. No.: 290,392

[52] U.S. C1 51/13, 241/171, 259/30 [51] Int. Cl B24b 3/26 [58] Field of Search 51/13, 9, 164, 163;

[56] References Cited UNITED STATES PATENTS 2,642,392.6/l953 Sommers 551/164 3.540.155 11/1970 Walkeretal. ..51/9

3,726,046 4/1973 Dreher 51/13 X FOREIGN PATENTS OR APPLICATIONS 1,097,852 7/1961 Germany 51/164 Primary Examiner-A1 Lawrence Smith Assistant Examine rNicholas P. Godici Attorney, Agent, or Firm-Fitzpatrick, Cella. Harper & Scinto [57] ABSTRACT A workpiece treatment machine wherein a workpiece holding basket is retained between a pair of rotatable support elements and wherein said basket is pivotally connected to the elements near its periphery and othv erwise releasably connected to the support elements so that as they are rotated in a particular direction the basket will roll out from the machine for treatment.

13 Claims, 7 Drawing Figures PATENTEDJUNI 1 1514 3.815 28 7 SHEET 1 BF 3 Ti Q .2

52 Den/5 Abmg 5O THY HM:

IWIIW PATGNTEBJUHH IBM 3815287 SHEET 2 0F 3 WORKPIECE TREATMENT MACHINE WITH DISCHARGE MEANS This invention relates to workpiece treatment machines having dumping mechanisms and more particularly it concerns a self actuating mounting arrangement for workpiece carrying baskets which allow such baskets to be unloaded by dumping with a minimum of effort.

The present invention is particularly well suited for use in connection with abrasive blasting apparatus of the type shown and described in US. Pat. Nos. 2,752,732 and 3,540,155. The blasting apparatus described in those patents includes a pair of paddle type impellers which throw abrasive shot upwardly toward a cylindrical rotating workpiece containing basket.

workpieces whose surfaces are to be treated are tumbled inside the basket; and the thrown shot passes through perforate walls of the basket and impinges on the various surfaces of the workpieces being tumbled therein to clean or polish them.

The workpiece basket and the impeller blades are cated within an outer housing which serves to contain the shot for recovery and recycling as well as to prevent dust and shot from contaminating the atmosphere. A housing door is provided at the front of the housing; and door means are provided on the workpiece basket for permitting the workpieces to be placed into and removed from the basket.

The basket loading and unloading arrangements of the prior art have various drawbacks which the present invention serves to overcome. With prior art devices it is necessary to hand load and unload the workpiece basket. This requires reaching inside the housing of the machine itself in order to deposit and remove workpieces. The physical handling of workpieces, especially during unloading may be undesirable in several respects. Firstly, the unloading operation requires considerable time since the individual workpieces have to be removed by hand; This results in undesirable delays, especially where very small workpieces have been processed. Secondly, the weight, temperature and con means is operable to move the basket from an operating position inside the housing to a dumping position outside the housing. Means are also provided for rotating the basket inside the housing.

In the preferred embodiment, the special mounting means comprises a pair of spaced apart rotatable support elements between which the basket is mounted and which rotate to turn the basket about its own axis. The basket is at least partially releasable from the support elements and linkage means are provided whereby the basket, when released, rolls out from inside the machine to a dumping position. The basket contains an openable door on its cylindrical surface; and this door is located at or near the underside of the basket when it reaches its dumping position so that when the door is opened the contents of the container may fall into a receiving bin. l

Also, in the preferred embodiment illustrated herein, thebasket is pivotally connected near its periphery to each of the rotatable support elements so that the bas-' ket can pivot or roll outfrom between the elements. Releasable connecting means are provided to maintain the basket axis aligned with the rotatableelement axis tours of the workpieces may pose a strain upon or a The invention, in its different aspects, is directed to overcoming the above-described problems. With the present invention a workpiece basket is unloaded automatically by dumping at the end of an abrading or blasting operation. This dumping, moreover, takes place by movement of the workpiece basket to a location outside the machine. In addition, the dumping operation maybe effected without the operator having to lift the basket; and the actual basket movement and dumping may be carried out simply by controlling the basket rotating motor in the machine.

According to the present invention, a cylindrical workpiece basket is mounted in special mounting means within the machine. This special mounting during the blasting operation. When this operation is completed and the machine housing door is opened, the releasable connecting means is released; and the basket rolls out by pivoting about its pivoted connection to the rotatable support elements. This basket rollout is powered by reverse rotation of the basket drive motor in the machine. a

The present invention, in one aspect, takes advantage of load weight shifts of the basket to initiate the basket rollout operation. According to this aspect, the rotatable support elements are turned a small amount in the normal working direction after the releasable connecting means is released. The continued rotation-causes the load weight shift with respect to the pivotal connection between the basketand the rotatable support elements. When this occurs the load weight causesthe basket to pivot about that-pivotal connection so that basket rollout from the machine begins. The basket then drops down onto support or guide rails along which it rolls out from the machine. The direction of rotation of the support elements is then reversed and rotation is continued for about until the basket reaches its maximum rollout position.

After the dumping operation is completed, the rotatable support elements are turned in their normal abrading direction and the basket rolls back into close alignment with the axis of rotation of the support elements. When the basket reaches a position of close alignment it may be pushed into operating position; or, if desired, the rotatable support elements may be rotated a further amount until the weight of the basket brings it into full alignment with the support elements. The releasable connecting means are reconnected. The basket may be reloaded and a new abrading operation commenced.

A specific embodiment of the invention has been chosen for purposes of illustration and description. and is shown in the accompanying drawing, forming a part of the specification, wherein:

H6. 1 is a front elevational view, partially cut away. of a blasting machine in which the present invention is embodied;

FIG. 2 is a section view taken along line 2-2 of FIG.

FIG. 3 is a fragmentary perspective view of a workpiece holding basket and basket mounting arrangement of the machine of FIGS. 1 and 2; and

FIGS. 4-7 are partial schematic views showing, re spectively, the relative positions between the workpiece basket and basket mounting arrangements during successive steps in a basket dumping operation of the machine of FIGS. 1 and 2.

The blasting machine shown in FIGS. 1 and 2 includes an outer housing made up of a top wall 12, a pair of side walls 14 and 16 (FIG. 1) a bottom wall 18 a back wall 20 (FIG. 2) and a front wall 22 (FIG. 2). The front wall 22 is provided with an opening 24 in the upper region thereof; and this opening is covered during normal operation by a cover door 26.

A cylindrical workpiece support basket 28 is mounted inside the upper region of the housing 10 to rotate about a horizontal axis 30 extending between the sidewalls l4 and 16. The basket 28 has a cylindrical outer wall 32 of perforate or open construction so as to contain workpieces to be treated and at the same time to allow shot or abrasive material thrown against the basket to pass through the outer wall and impinge against the workpieces. Disk like end walls 34 cover the opposite ends of the cylindrical outer wall 32. These end walls have a slightly larger diameter than that of the cylindrical outer wall 32; and retaining rods 36, 38, and 42 pass between the end walls 34 just outside outer wall 32. These retaining rods include a door locking rod 36, a basket pivot rod 38, a permanent retaining rod 40 and a rollout limiting rod 42. All of these rods are connected at their opposite ends to rotatable support elements 44 located inside the housing 10 adjacent the basket end walls 34. The rotatable support elements 44 also are disk shaped; and they are provided with hubs 46 which extend outwardly from their centers. These hubs pass through the side walls 14 and 16 of the outer housing 10 and are there supported for rotation by means of bearings 48.

A reversible basket drive motor 50 (FIG. 1) is mounted on the machine and is connected via sprockets 52 and 54 and a drive chain 56 to the hub 46 of one of the support element hubs 46. In this way the basket drive motor 50 turns the rotatable support elements 44 and these elements, operating through the various retaining rods 36, 38, 40 and 42 serve to turn the workpiece basket 28.

A pair of paddle wheels 58 (FIG. 1) are mounted for rotation inside the lower portion of the outer housing 10 below the workpiece basket 28. These paddle wheels may have axles 60 which are supported in bearings 62. As shown in FIG. 2 a paddle drive motor 64 is connected by means of pulleys 66 and 68 and a belt 70 to the axles 60 to drive the paddle wheels 58 so that they hurl shot up toward the basket 28.

The paddle wheels 58 are located within a paddle casing formed by vertical walls 72 located adjacent the paddle wheel blades within the lower portion of the housing 10. Hopper walls 74 extend outwardly and upwardly from the sides of the paddle casing just above the axles 60. These hopper walls collect spent shot which has fallen from the basket 28 and direct it through openings 76 in the vertical walls 72 and into the path of the paddle wheel blades so that it will again be thrown by the rotating blades back up to the basket 28.

A vacuum exhaust system (not shown) is provided for elimination of dust and shot which is too fine to be reused. A-separator 77 is mounted on the rear of the housing and is connected to the vacuum exhaust system through an exhaust duct 78. j

Turning now to FIG. 3 it will be seen that the end walls 34 of the basket 28 are formed with retaining rod notches 80 and 82 which open out to the periphery of these disks. The notches 80 and 82 are located diametrically opposite each other on the end walls 34 and they accommodate the door locking rod 36 and the permanent rod 40. The pivot rod 38, it will be noted, does not pass through a notch, but instead it passes through pivot openings 84. These openings are formed cooperatively between notches 84a and 84b in the basket end walls 34 and in removable plates 85 mounted on the end walls. When the end plates 85 are removed, the basket may be slipped off the pivot rod for repair or replacement.

Latch notches 86 are located on the periphery of the end walls 34 diametrically opposite the pivot openings 84. These latch notches accommodate the rollout limiting rod 42.

A rollout limiting link 88 is provided on each side of the basket 28 between the basket end walls 34 and their corresponding rotatable support elements 44. The lower ends of these links 88 are pivotally connected to the basket end walls 34 at a location approximately half way rotationally between the pivot opening 84 and the permanent rod notch 82 and approximately three fourths of the distance from the center to the periphery of the end wall. The upper end of the link 88 is provided with a link slot 90 which accommodates the rollout limiting rod 42. It will be appreciated that because the lower ends of the rollout limiting links 88 are pivoted to the end walls 34 at locations offset with respect to their centers, the upper end of the links (and the rod 42 carried by them) will upon pivoting of the links, follow an are which intersects the periphery of the end walls 34 at the latch notches 86 as the links pivot clockwise as viewed in FIG. 3. Reverse rotation of the links will free the limiting rod 42 from the latch notches 86. It will be noted that the latch notches 86 are of asymmetrical configuration to accommodate this relative movement of the end walls 34 and the rollout limiting rod 42.

A segment of the cylindrical outer wall 32 of the basket 28 is longitudinally hinged to the remainder of the wall along a hinge line 92 to form a basket loading door 94. This door is positioned adjacent the door locking rod 36 and is held closed by this rod during operation of the machine.

The door locking rod 36 is detachably secured to the rotational support elements 44. Any convenient form of detachable connection may be employed. One such arrangement, shown in detail in FIG. 4 of U. S. Pat. application Ser. No. 141,716, filed May 10, 1971, involves the provision of spring steel strips on the outer surfaces of the support elements for the rod so that they cover holes in the elements through which the rod passes. The rod is removed by forcing-it longitudinally against one of the spring strips until the other end of the rod is freed from the hole in the opposite element. The freed rod end is directed away from its element and the rod is then moved logitudinally in the opposite direction to free it from the basket. The basket door may now be opened. Spring steel retaining clips 96 as above described, are shown on the outer surfaces of the support elements 44 in FIG. 1. a

A pair of rollout guide rails 98 are located under the basket end walls 34; and as shown in FIG. 1 these rails extend from a vertical line intersecting the normal basket-axis to the lower edge of the housing opening 24. When the basket 28 is in its normal operating position and supported by the rotatable support elements 44 as shown in FIG .,2, the basket end walls 34 are located a slight distance e.g., one half inch, above the guide rails 98.

A basket return mechanism is shown in association with one of the guide rails 98 in FIG. 3. As can be seen one of the rails is formed with a longitudinal slot 100 in which a lift strip 102 extends. The .outermost end of the lift strip rests on a step 104 just under the front edge of the slot 100. The innermost end of the lift strip is pivoted to the guide rail and is connected to a crank arm 106 which is operative to pivot the lift strip from a position flush with the rail 98 to a basket lifting position as shown in F IG.'3. This action may be used to lift the basket from the guide-rails 98 up (approximately one half inch) to the support elements 44.

During normal operation of the above described machine, the basket 28, containing workpiece elements, and supported by the support elements 44 rotates inside the housing 10 as shown in solid outline FIG. 2, while the paddle wheels 58 hurl abrasive shot up toward the basket. Workpiece elements are tumbled in the basket and are cleaned or othewise treated by the particles which pass through the perforate cylindrical wall 32 of thebasket.

After the treating operation is completed the cover.

door 26 is opened, and the door locking retaining rod 36 is detached as above described. The workpiece basket is then moved from its solid line position, shown in FIG. 2, toa dumping position out through the front opening 24, as shown in phantom outline in FIG. 2. The basket loading door 94 pivots downwardly by gravity and the treated workpieces (not shown) automatically dump out from thebasket and into any suitable container or bin which may be placed in front of the machine. g

The outward movement and dumping of the basket 28 is powered and controlled solely by the basket drive motor 50 operating in conjunction with the rotatable support elements 44, the retaining rods 38, 40 and 42 and the rollout limiting links 88. The manner in which these elements function together to produce this basket rollout action will now be described.

FIGS. 4-7 illustrate schematically the mechanical linkage arrangement which operates to cause basket rollout to a dumping position by means of basket rotation control.

As indicated in FIG. 4, the basket 28 is supported by its end walls 34 resting within the retaining rods 36, 38, 40 and 42. These rods, which are heldat their ends by the rotational support elements 44, are turned by these elements to revolve about the basket axis thereby to rotate the basket in a clockwise direction as indicated by the arrow A.

In order to initiate the basket dumping sequence, the basket rotation is stopped with the basket door 94 facing the housing opening 24, i.e., facing rightwardly as shown in FIG. 4. The door locking rod 36 is removed as above described and the basket 28 is then rotated a further small amount in the clockwise direction to the position'shown in FIG. 5.

This slight additional rotation shifts the center of gravity of the load rightwardly with respect to the pivot rod 38, as indicated by, the arrow B. This sets up a clockwise torque about the pivot rod 38 as indicated by the arrow C. Since the door locking rod 36 has been removed no resistance is provided to the arrow C torque and the basket 28 pivots around the rod 38 and swings out from between the rotational support elements. This pivoting movement of the basket is intercepted by the guide rails 98 as the basket end walls 34 fall down on them as shown in FIG. .6. It will be noted that during this movement the end wall notches retaining rod notches 82 allow the end walls 34 to swing away from the permanent rod 40. Also, the asymmetrical latch notches 86 allow the .end walls 34 to swing out free from the rollout limiting rod 42 while the slots in the rollout limiting links 88 permits the rods, which are pivoted at their lower ends to the end walls 34, also to accommodate this initial rollout movement.

At this point, the direction of rotation of the rotatable support elements 44 is reversed from clockwise to counterclockwise as indicated by the arrow D in FIG. 6. The only positive connection at this point between the rotational support elements 44 and the basket end walls 34 is via the pivotrod 38 so that the reverse rotation of the rotatable support elements 44 imposes a force in the direction of the arrow B via the pivot rod 38 onto the basket end walls 34. Since the end walls 34 are now rollingly engaged with the guide rails 98, the force indicated by'the arrow E produces a clockwise torque indicated by the arrow F about the points of contact between the end walls 34 and the guide rails 98. This torque causes the basket 28 to roll outwardly along the guide rails 98 tothe dumping position shown in FIG. 7. I

The outward basket rotation is continued by maintaining the counterclockwise rotation of therotatable support elements 44 until they bringthe rollout limiting rod 42 around to a position where it encounters the outermost extremity of the slots 90 in the rollout limit .ing link 88 as shown in FIG. 7. This prevents the basket from rolling off the ends of the guide rails 98. If neces' sary or desired, the counterclockwise rotationof the rotational support elements 44 may be continued to lift the basket 28 clear of the guide rails so that it is supported sloely by the rotational support elements 44 operating on the one hand through the pivot rod 38 and on. the other hand through the rollout limiting rod 42 and the limiting links 88.

After the 'basket28 has been dumped it may be returned to its initialposition by rotating the support ele ments clockwise until the basket has rolled back along the guide rails 98 to the position shown in .FIG. 6. At this point, the crankarm 106 of the basket return mechanism (FIG. 3) is operated to pivot the lift strip 102.. The lift strip engages one of the basket end walls 34and lifts the basket up into alignment with the rotational support elements 44. At this point the rotational support elements are pivoted to a position slightly counter clockwise of that shown in FIG. 4 so that the basket 28 is cradled between the pivot rod 38 and the permanent rod 40. The basket may then be loaded without rolling outfrom between the support elements. After loading,

the basket loading door 94 is closed and the door lock ing rod 36 replaced for a subsequent treatment operation.

If desired, the operation of the lifting mechanism may be eliminated in the basket return sequence. This may be done by continuing clockwise rotation of the rotatable support elements nearly a full turn after the basket has reached a position where the lifting mechanism would have been operated. This continued turning will eventually bring the basket center of gravity to a position where its own weight will swing it into rested position among the retaining rods. Thus, it is possible to obtain both dumping rollout and loading return of the basket without application of manual effort.

Having thus described the invention with particular reference to the preferred form thereof, it will be obvious to those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made therein without departing from the spirit and scope of the invention, as defined by the claims appended hereto.

I claim:

1. In a treatment machine wherein articles are tumbled in a rotating basket which turns within an outer housing, the combination of mounting means for said basket and operable to move said basket from an operating position inside said housing to a dumping position outside said housing, and basket rotating means operable to cause said basket to turn within said housing, said mounting means including releasable connecting means operable to hold said basket engaged with said mounting means and means for transmitting movement of said basket rotating means to said basket at a location thereon which causes said basket to roll out to its said dumping position.

2. A treatment machine according to claim 1 wherein said means for transmitting movement of said basket rotating means comprises a pair of rotatable support elements between which said basket is held and linkage means for guiding movement of the basket out from between the rotational support elements.

3. A treatment machine according to claim 2 wherein said linkage means includes a pivotal interconnection between said basket near its periphery and at least one of said support elements whereby said basket may rollout from between said elements.

4. A treatment machine according to claim 2 wherein said linkage means includes a rollout limiting link interconnected between said basket and said rotatable support elements.

5. A treatment machine according to claim 1 wherein said releasable connecting means includes means for preventing relative rotation of said basket and said support elements about said pivotal interconnection.

6. A treatment machine according to claim 1 wherein said basket has a door pivotally mounted thereon and wherein said door is held closed by said releasable connecting means.

7. in a treatment machine wherein articles are tumbled in a rotary workpiece holding basket during treatment of said articles, the combination of mounting means for said basket, said mounting means comprising a pair of spaced apart rotatable support elements, said support elements being mounted in said machine for rotation about a common axis, pivotal connecting means on each of said support means, said pivotal connecting means being displaced from said common axis and pivotally connected to a corresponding end of said basket at corresponding locations thereon, releasable connecting means arranged, when connected, to prevent relative rotation between said basket and said support elements, basket rollout limit means for limiting the extent of relative rotation between said basket and said support elements and means for rotatably driving at least one of said support elements.

8. A treatment machine according to claim 7 wherein said releasable connecting means comprises an element selectively engageable with said basket and at least one of said support elements at a location displaced from said pivotal connecting means.

9. A treatment machine according to claim 7 wherein said basket rollout limit means comprises a link connected between said basket and said support means, said link being arranged to allow a limited degree of relative rotation between said basket and said support elements.

10. A treatment machine according to claim 7 wherein said basket is formed on its ends with end plates which extend out beyond the. periphery of said basket and wherein said basket is held between said rotary support elements by means of retaining rods extending between said support elements, said rods passing through openings in said end plates.

11. A treatment machine according to claim 10 wherein at least one of said rods constitutes said pivotal connecting means and wherein the plate openings for the other rods is open to the periphery of the end plates for allowing the basket to roll out from between the support elements.

12. A treatment machine according to claim 11 wherein another of said rods constitutes said releasable connecting means, said other rod being releasable and removable from between said support elements to allow relative rotation between said basket and said support elements.

- 13. A treatment machine according to claim 12 wherein a still further one of said rods forms a portion of said rollout limit means, said rollout limit means fur ther. comprising a link pivotally interconnected between said still further rod and one of said basket end plates, said link being slotted at one end to allow limited relative rotation between said basket and said sup port elements. 

1. In a treatment machine wherein articles are tumbled in a rotating basket which turns within an outer housing, the combination of mounting means for said basket and operable to move said basket from an operating position inside said housing to a dumping position outside said housing, and basket rotating means operable to cause said basket to turn within said housing, said mounting means including releasable connecting means operable to hold said basket engaged with said mounting means and means for transmitting movement of said basket rotating means to said basket at a location thereon which causes said basket to roll out to its said dumping position.
 2. A treatment machine according to claim 1 wherein said means for transmitting movement of said basket rotating means comprises a pair of rotatable support elements between which said basket is held and linkage means for guiding movement of the basket out from between the rotational support elements.
 3. A treatment machine according to claim 2 wherein said linkage means includes a pivotal interconnection between said basket near its periphery and at least one of said support elements whereby said basket may rollout from between said elements.
 4. A treatment machine according to claim 2 wherein said linkage means includes a rollout limiting link interconnected between said basket and said rotatable support elements.
 5. A treatment machine according to claim 1 wherein said releasable connecting means includes means for preventing relative rotation of said basket and said support elements about said pivotal interconnection.
 6. A treatment machine according to claim 1 wherein said basket has A door pivotally mounted thereon and wherein said door is held closed by said releasable connecting means.
 7. In a treatment machine wherein articles are tumbled in a rotary workpiece holding basket during treatment of said articles, the combination of mounting means for said basket, said mounting means comprising a pair of spaced apart rotatable support elements, said support elements being mounted in said machine for rotation about a common axis, pivotal connecting means on each of said support means, said pivotal connecting means being displaced from said common axis and pivotally connected to a corresponding end of said basket at corresponding locations thereon, releasable connecting means arranged, when connected, to prevent relative rotation between said basket and said support elements, basket rollout limit means for limiting the extent of relative rotation between said basket and said support elements and means for rotatably driving at least one of said support elements.
 8. A treatment machine according to claim 7 wherein said releasable connecting means comprises an element selectively engageable with said basket and at least one of said support elements at a location displaced from said pivotal connecting means.
 9. A treatment machine according to claim 7 wherein said basket rollout limit means comprises a link connected between said basket and said support means, said link being arranged to allow a limited degree of relative rotation between said basket and said support elements.
 10. A treatment machine according to claim 7 wherein said basket is formed on its ends with end plates which extend out beyond the periphery of said basket and wherein said basket is held between said rotary support elements by means of retaining rods extending between said support elements, said rods passing through openings in said end plates.
 11. A treatment machine according to claim 10 wherein at least one of said rods constitutes said pivotal connecting means and wherein the plate openings for the other rods is open to the periphery of the end plates for allowing the basket to roll out from between the support elements.
 12. A treatment machine according to claim 11 wherein another of said rods constitutes said releasable connecting means, said other rod being releasable and removable from between said support elements to allow relative rotation between said basket and said support elements.
 13. A treatment machine according to claim 12 wherein a still further one of said rods forms a portion of said rollout limit means, said rollout limit means further comprising a link pivotally interconnected between said still further rod and one of said basket end plates, said link being slotted at one end to allow limited relative rotation between said basket and said support elements. 